Discussion 8: Link State Routing. CSE 123: Computer Networks Marti Motoyama & Chris Kanich

Size: px
Start display at page:

Download "Discussion 8: Link State Routing. CSE 123: Computer Networks Marti Motoyama & Chris Kanich"

Transcription

1 iscussion 8: Link State Routing S : omputer Networks Marti Motoyama & hris Kanich

2 Schedule Project Questions: mail hris, post to moodle, or attend his OH Homework Questions? Link State iscussion S iscussion 8

3 utonomous Systems utonomous systems: a network that is under the control of a single administrative entity Goals: Internet is not a single network; it is composed of multiple Ses (e.g. US, ISPs, big corporations, etc.) Ses want to choose their own local routing algorithms (intradomain routing)» Link State, e.g., Open Shortest Path First (OSPF)» istance Vector, e.g., Routing Information Protocol (RIP) Ses want to set policies about non-local routing (interdomain routing)» order Gateway Routing (GP), which you ll see later. S iscussion 8

4 Internet Today Figure 4.9 in the book ach oval corresponds to a different S You will learn more about this picture in later lectures S iscussion 8 4

5 Routing We mentioned the term routing First, let s make distinction between what you ve seen previously, forwarding. Forwarding (data plane): moving packets between ports Look up the destination address in forwarding table Locate {out-port} or {out-port, M address} pair Routing (control plane): process of populating forwarding table Routers exchange messages about networks they can reach Goal is to find an optimal route for every destination S iscussion 8

6 Routing Strategies Routing requires knowledge of the network structure This is often sensitive information entralized global state: Single entity knows the complete network structure, can calculate all routes centrally Problems with this approach? istributed, global state: very router knows the complete network structure, routers can independently calculate routes Problems with this approach? istributed, no-global state: very router knows only about its neighboring routers, routers can independently calculate routes Problems with this approach? S iscussion 8 6

7 Modeling a Network F Modeled a network as a graph: Routers nodes Links edges» ssociated with each edges is a cost» What are some metrics you might use as cost? Latency, bandwidth, utilization, queue length, etc S iscussion 8 7

8 Link State: ontrol Traffic ach node floods its local information to every other node in the network ach node knows the entire network topology and can compute shortest paths to other nodes using ijkstra s Host Host Host N N N N Host N4 Host N6 N7 S iscussion 8 8

9 Link State: Node State Host Host Host N N N N Host N4 Host N6 N7 S iscussion 8 9

10 Link State Question Name some problems that would arise if all routing in the Internet was done using Link-State and ijkstra s algorithm. S iscussion 8 0

11 Implementing Link State Routing s given in the book on page 8 s always, intimately understand version given in lecture Overview: ach node maintains two lists:» Tentative (similar to Q): nodes whose shortest paths still need to be computed, we know about their existences» onfirmed (similar to S): nodes whose shortest paths are known ach list contains entries of the type:» {estination, ost, Next Hop}. The two lists are continuously updated as new nodes are added to the shortest path tree (as in the ijkstra s algorithm). S iscussion 8

12 ook lgorithm in Gory etail. Initialize onfirmed list with myself, cost = 0. For node Next added to onfirmed in the previous step, select its LSP. all NextHop the node used to reach Next.. For each neighbor of Next, calculate cost to reach Neighbor ost(me, Neighbor) = ost(me, Next) + ost(next, Neighbor) a) If Neighbor not on Tentative or onfirmed: dd {Neighbor, ost, NextHop} to Tentative b) If Neighbor is on Tentative: If cost computed is less than the cost currently listed for Neighbor, replace the entry with {Neighbor, ost, NextHop}. lse, do nothing. 4. If Tentative list is empty, stop. lse, pick entry from the Tentative list with lowest cost and move it to onfirmed list. Return to Step. S iscussion 8

13 Link State xample F Problem: uild routing table for Initialize onfirmed list with myself, cost = 0 Step onfirmed Tentative (, 0, -) S iscussion 8

14 Link State xample F If Neighbor not on Tentative or onfirmed: add {Neighbor, ost, NextHop} to Tentative Step onfirmed Tentative (, 0, -) (,,), (,,), (,,) S iscussion 8 4

15 Link State xample F Pick entry from the Tentative list with lowest cost and move it to onfirmed list. Step onfirmed Tentative (, 0, -), (,,) (,,), (,,), S iscussion 8

16 Link State xample Node Next If Neighbor is on Tentative: If cost computed is less than the cost currently listed for Neighbor, replace the entry with {Neighbor, ost, NextHop}. lse, do nothing. Step onfirmed Tentative 4.i (, 0, -), (,,) (,,), (, 4, ), F S iscussion 8 6

17 Link State xample Node Next If Neighbor not on Tentative or onfirmed: add {Neighbor, ost, NextHop} to Tentative F Step onfirmed Tentative 4.ii (, 0, -), (,,) (,,), (,4,), (,,), S iscussion 8 7

18 Link State xample nd so on F Final Routing Table: Step onfirmed Tentative? (,0,-),(,,),(,,), (,,),(,,),(F,4,) S iscussion 8 8

19 The Forwarding Table Running ijkstra at node gives the shortest path from to all destinations We then construct the forwarding table estination Interface if if if0 F if0 F S iscussion 8 9

20 omplexity How much processing does running the ijkstra algorithm take? ssume a fully connected network with N nodes: ach iteration: need to check all nodes not in onfirmed» st iteration: search through all (N-) nodes in Tentative to find one with minimum cost» nd iteration: search through all (N-) nodes in Tentative to find one with minimum cost» ~N(N+)/ comparisons O(N ) More efficient implementations possible using sorting algorithms O(N log(n)) S iscussion 8 0

21 Obtaining Global State Flooding ach router sends link-state information out its links The next node sends it out through all of its links» xcept the one where the information arrived X X (a) (b) X X (c) (d) S iscussion 8

22 Flooding the Link State Reliable flooding nsure all nodes receive link-state information nsure all nodes use the latest version hallenges: Packet loss Out-of-order arrival Solutions: cknowledgments and retransmissions Sequence numbers Time-to-live for each packet S iscussion 8

23 Flooding the Link State Topology change Link or node failure Link or node recovery onfiguration change Link cost change oping with a dynamic environment: Periodically refresh the link-state information Typically (say) 0 minutes orrects for possible corruption of the data S iscussion 8

24 Link osts bout those link costs... Importance of ost Metric: hoice of link cost defines traffic load Low cost = high probability that link belongs to shortest path tree and will attract traffic, which increases cost Main problem: convergence Want to avoid oscillations while achieving good network utilization S iscussion 8 4

25 Link ost Question xplain why using a static cost metric like hop count is a bad idea. S iscussion 8

26 Load Sensitivity Question ssume the routing protocol computes the shortest path, where the cost of a link represents its traffic load (i.e., the amount of traffic on the link). The traffic from to represents the only traffic in the network. Which route is the traffic from to going to use? Is the route stable? xplain why, or why not. S iscussion 8 6

27 Load Sensitivity Question ssume the traffic from to is TP and assume that the roundtrip time along is much higher than the round-trip-time along. What are some negative impacts of the loadsensitive routing algorithm on TP performance? onsider the effects in particular on TP that implements fast retransmission. S iscussion 8 7

What is Routing? EE 122: Shortest Path Routing. Example. Internet Routing. Ion Stoica TAs: Junda Liu, DK Moon, David Zats

What is Routing? EE 122: Shortest Path Routing. Example. Internet Routing. Ion Stoica TAs: Junda Liu, DK Moon, David Zats What is Routing? Routing implements the core function of a network: : Shortest Path Routing Ion Stoica Ts: Junda Liu, K Moon, avid Zats http://inst.eecs.berkeley.edu/~ee/fa9 (Materials with thanks to Vern

More information

ECE 158A: Lecture 5. Fall 2015

ECE 158A: Lecture 5. Fall 2015 8: Lecture Fall 0 Routing ()! Location-ased ddressing Recall from Lecture that routers maintain routing tables to forward packets based on their IP addresses To allow scalability, IP addresses are assigned

More information

Let s focus on clarifying questions. More Routing. Logic Refresher. Warning. Short Summary of Course. 10 Years from Now.

Let s focus on clarifying questions. More Routing. Logic Refresher. Warning. Short Summary of Course. 10 Years from Now. Let s focus on clarifying questions I love the degree of interaction in this year s class More Routing all Scott Shenker http://inst.eecs.berkeley.edu/~ee/ Materials with thanks to Jennifer Rexford, Ion

More information

TCP/IP Networking. Part 3: Forwarding and Routing

TCP/IP Networking. Part 3: Forwarding and Routing TP/IP Networking Part 3: Forwarding and Routing Routing of IP Packets There are two parts to routing IP packets:. How to pass a packet from an input interface to the output interface of a router ( IP forwarding

More information

CS 43: Computer Networks. 23: Routing Algorithms November 14, 2018

CS 43: Computer Networks. 23: Routing Algorithms November 14, 2018 S 3: omputer Networks 3: Routing lgorithms November, 08 Last class NT: Network ddress Translators: NT is mostly bad, but in some cases, it s a necessary evil. IPv6: Simpler, faster, better Tunneling: IPv6

More information

COMP 3331/9331: Computer Networks and Applications

COMP 3331/9331: Computer Networks and Applications OMP /9: omputer Networks and pplications Week 9 Network Layer: Routing Reading Guide: hapter 4: Sections 4.5 Network Layer nnouncements v Labs Lab 4 ongestion ontrol Lab 5 Simple Router (start up for ssignment,

More information

WAN Technology and Routing

WAN Technology and Routing PS 60 - Network Programming WN Technology and Routing Michele Weigle epartment of omputer Science lemson University mweigle@cs.clemson.edu March, 00 http://www.cs.clemson.edu/~mweigle/courses/cpsc60 WN

More information

EE 122: Intra-domain routing

EE 122: Intra-domain routing EE : Intra-domain routing Ion Stoica September 0, 00 (* this presentation is based on the on-line slides of J. Kurose & K. Rose) Internet Routing Internet organized as a two level hierarchy First level

More information

Routing. Effect of Routing in Flow Control. Relevant Graph Terms. Effect of Routing Path on Flow Control. Effect of Routing Path on Flow Control

Routing. Effect of Routing in Flow Control. Relevant Graph Terms. Effect of Routing Path on Flow Control. Effect of Routing Path on Flow Control Routing Third Topic of the course Read chapter of the text Read chapter of the reference Main functions of routing system Selection of routes between the origin/source-destination pairs nsure that the

More information

Lecture 9. Reminder: Homework 3, Programming Project 2 due today. Questions? Thursday, September 22 CS 475 Networks - Lecture 9 1

Lecture 9. Reminder: Homework 3, Programming Project 2 due today. Questions? Thursday, September 22 CS 475 Networks - Lecture 9 1 Lecture 9 Reminder: Homework 3, Programming Project 2 due today. Questions? Thursday, September 22 CS 475 Networks - Lecture 9 1 Outline Chapter 3 - Internetworking 3.1 Switching and Bridging 3.2 Basic

More information

CS 457 Networking and the Internet. Shortest-Path Problem. Dijkstra s Shortest-Path Algorithm 9/29/16. Fall 2016

CS 457 Networking and the Internet. Shortest-Path Problem. Dijkstra s Shortest-Path Algorithm 9/29/16. Fall 2016 9/9/6 S 7 Networking and the Internet Fall 06 Shortest-Path Problem Given: network topology with link costs c(x,y): link cost from node x to node y Infinity if x and y are not direct neighbors ompute:

More information

COMP/ELEC 429/556 Introduction to Computer Networks

COMP/ELEC 429/556 Introduction to Computer Networks OMP/ELE 49/6 Introduction to omputer Networks Intra-domain routing Some slides used with permissions from Edward W. Knightly, T. S. Eugene Ng, Ion Stoica, Hui Zhang T. S. Eugene Ng eugeneng at cs.rice.edu

More information

4/25/12. The Problem: Distributed Methods for Finding Paths in Networks Spring 2012 Lecture #20. Forwarding. Shortest Path Routing

4/25/12. The Problem: Distributed Methods for Finding Paths in Networks Spring 2012 Lecture #20. Forwarding. Shortest Path Routing //1 The Problem: istributed Methods for Finding Paths in Networks L 1.0 Spring 01 Lecture #0 addressing, forwarding, routing liveness, advertisements, integration distance-vector routing link-state routing

More information

Network service model. Network service model. Network Layer (part 1) Virtual circuits. By the end of this lecture, you should be able to.

Network service model. Network service model. Network Layer (part 1) Virtual circuits. By the end of this lecture, you should be able to. Netork Layer (part ) y the end of this lecture, you should be able to. xplain the operation of distance vector routing algorithm xplain shortest path routing algorithm escribe the major points of RIP and

More information

Routers & Routing : Computer Networking. Binary Search on Ranges. Speeding up Prefix Match - Alternatives

Routers & Routing : Computer Networking. Binary Search on Ranges. Speeding up Prefix Match - Alternatives Routers & Routing -44: omputer Networking High-speed router architecture Intro to routing protocols ssigned reading [McK9] Fast Switched ackplane for a Gigabit Switched Router Know RIP/OSPF L-4 Intra-omain

More information

Overview. Problem: Find lowest cost path between two nodes Factors static: topology dynamic: load

Overview. Problem: Find lowest cost path between two nodes Factors static: topology dynamic: load Dynamic Routing Overview Forwarding vs Routing forwarding: to select an output port based on destination address and routing table routing: process by which routing table is built Network as a Graph C

More information

06/02/ Local & Metropolitan Area Networks. Overview. Routing algorithm ACOE322. Lecture 6 Routing

06/02/ Local & Metropolitan Area Networks. Overview. Routing algorithm ACOE322. Lecture 6 Routing Local & Metropolitan rea Networks OE3 Lecture 6 Routing r. L. hristofi Overview The main function of the network layer is routing packets from the source to the destination machine. The only exception

More information

IP Forwarding Computer Networking. Routes from Node A. Graph Model. Lecture 10: Intra-Domain Routing

IP Forwarding Computer Networking. Routes from Node A. Graph Model. Lecture 10: Intra-Domain Routing IP orwarding - omputer Networking Lecture : Intra-omain Routing RIP (Routing Information Protocol) & OSP (Open Shortest Path irst) The Story So ar IP addresses are structure to reflect Internet structure

More information

Distance-Vector Routing: Distributed B-F (cont.)

Distance-Vector Routing: Distributed B-F (cont.) istance-vector Routing: istributed - (cont.) xample [ istributed ellman-ord lgorithm ] ssume each node i maintains an entry (R(i,x), L(i,x)), where R(i,x) is the next node along the current shortest path

More information

C13b: Routing Problem and Algorithms

C13b: Routing Problem and Algorithms CISC 7332X T6 C13b: Routing Problem and Algorithms Hui Chen Department of Computer & Information Science CUNY Brooklyn College 11/20/2018 CUNY Brooklyn College 1 Acknowledgements Some pictures used in

More information

IP Forwarding Computer Networking. Graph Model. Routes from Node A. Lecture 11: Intra-Domain Routing

IP Forwarding Computer Networking. Graph Model. Routes from Node A. Lecture 11: Intra-Domain Routing IP Forwarding 5-44 omputer Networking Lecture : Intra-omain Routing RIP (Routing Information Protocol) & OSPF (Open Shortest Path First) The Story So Far IP addresses are structured to reflect Internet

More information

More Routing. EE122 Fall 2012 Scott Shenker

More Routing. EE122 Fall 2012 Scott Shenker More Routing EE Fall 0 Scott Shenker http://inst.eecs.berkeley.edu/~ee/ Materials with thanks to Jennifer Rexford, Ion Stoica, Vern Paxson and other colleagues at Princeton and UC Berkeley Let s focus

More information

Lecture 6: Bridging & Switching. Last time. Today. CSE 123: Computer Networks Chris Kanich. How do multiple hosts share a single channel?

Lecture 6: Bridging & Switching. Last time. Today. CSE 123: Computer Networks Chris Kanich. How do multiple hosts share a single channel? Lecture 6: ridging & Switching SE 3: omputer Networks hris Kanich Project countdown: 5 days Last time How do multiple hosts share a single channel? Medium ccess ontrol (M) protocols hannel partitioning

More information

Lecture 12: Link-state Routing. Lecture 12 Overview. Router Tasks. CSE 123: Computer Networks Chris Kanich. Routing overview

Lecture 12: Link-state Routing. Lecture 12 Overview. Router Tasks. CSE 123: Computer Networks Chris Kanich. Routing overview Lecture : Link-state Routing CSE 3: Computer Networks Chris Kanich Lecture Overview Routing overview Intra vs. Inter-domain routing Link-state routing protocols CSE 3 Lecture : Link-state Routing Router

More information

More on Network Routing and Internet Protocol

More on Network Routing and Internet Protocol omputer Networks //03 More on Network Routing and Internet Protocol Kai Shen Network Routing Link state routing: ijkstra s algorithm efficient approach to calculate least cost routes all routers need complete

More information

ÉCOLE POLYTECHNIQUE FÉDÉRALE DE LAUSANNE! 1. Link state flooding topology information finding the shortest paths (Dijkstra)

ÉCOLE POLYTECHNIQUE FÉDÉRALE DE LAUSANNE! 1. Link state flooding topology information finding the shortest paths (Dijkstra) ontents ÉOL POLYTHNIQU ÉÉRL LUSNN! 1. Link state flooding topology information finding the shortest paths (ijkstra)! 2. Hierarchical routing with areas! 3. OSP Link State Routing database modelling neighbor

More information

DSDV: Proactive. Distance Vector (Basic idea) Distance Vector. Distance Vector Algorithm: Tables 12/13/2016

DSDV: Proactive. Distance Vector (Basic idea) Distance Vector. Distance Vector Algorithm: Tables 12/13/2016 estination Sequenced istance Vector (SV) Routing [Perkins94] SV: Proactive SV is a proactive protocol means it maintains up-to-date routing information for all available nodes in the network. No extra

More information

Routing. 9: Intro to Routing Algorithms. Routing. Roadmap. Routing Algorithm classification: Static or Dynamic?

Routing. 9: Intro to Routing Algorithms. Routing. Roadmap. Routing Algorithm classification: Static or Dynamic? Routing 9: Intro to Routing lgorithms Last Modified: // :: PM : Netork Layer a- IP Routing each router is supposed to send each IP datagram one step closer to its Ho do they do that? Static Routing Hierarchical

More information

Network Layer (Routing)

Network Layer (Routing) Network Layer (Routing) Topics Network service models Datagrams (packets), virtual circuits IP (Internet Protocol) Internetworking orwarding (Longest Matching Prefix) Helpers: ARP and DHP ragmentation

More information

BTEC Level 3 Extended Diploma

BTEC Level 3 Extended Diploma BTEC Level 3 Extended Diploma Unit 9 Computer Network Routing and Routing Protocols BTEC Level 3 Extended Diploma Introduction to Routing Routing is the process that a router uses to forward packets toward

More information

Distance Vector Routing

Distance Vector Routing ÉOL POLYTHNIQU FÉÉRL LUSNN istance Vector Routing Jean Yves Le oudec 20 ontents. Routing in General 2. istance vector: theory 3. istance vector: practice (RIP) 4. Software efined Networking (SN) Textbook

More information

Review: Routing in Packet Networks Shortest Path Algorithms: Dijkstra s & Bellman-Ford. Routing: Issues

Review: Routing in Packet Networks Shortest Path Algorithms: Dijkstra s & Bellman-Ford. Routing: Issues Review: Routing in Packet Networks Shortest Path lgorithms: ijkstra s & ellman-ford Routing: Issues How are routing tables determined? Who determines table entries? What info used in determining table

More information

Advanced Computer Networks

Advanced Computer Networks istance Vector dvanced omputer Networks Internal routing - distance vector protocols Prof. ndrzej uda duda@imag.fr ontents Principles of internal routing istance vector (ellman-ford) principles case of

More information

Distributed Algorithms in Networks EECS 122: Lecture 17

Distributed Algorithms in Networks EECS 122: Lecture 17 istributed lgorithms in Networks EES : Lecture 7 epartment of Electrical Engineering and omputer Sciences University of alifornia erkeley Network Protocols often have unintended effects TP Eample TP connections

More information

EE122 MIDTERM EXAM: Scott Shenker, Ion Stoica

EE122 MIDTERM EXAM: Scott Shenker, Ion Stoica EE MITERM EXM: 00-0- Scott Shenker, Ion Stoica Last name Student I First name Login: ee- Please circle the last two letters of your login. a b c d e f g h i j k l m n o p q r s t u v w x y z a b c d e

More information

Performance and Evaluation of Congestion Control and Routing Algorithm for Improving Internet Traffic Control System

Performance and Evaluation of Congestion Control and Routing Algorithm for Improving Internet Traffic Control System IJN International Journal of omputer cience and Network ecurity, VOL. No.6, June 0 7 Performance and valuation of ongestion ontrol and Routing lgorithm for Improving Internet Traffic ontrol ystem.jayachandran,

More information

The Problem: Finding Paths Spring 2011 Lecture #19. Forwarding. Shortest Path Routing

The Problem: Finding Paths Spring 2011 Lecture #19. Forwarding. Shortest Path Routing The Problem: Finding Paths 1 6.02 Spring 20 Lecture # addressing, forwarding, routing liveness, advertisements, integration distance-vector routing routing loops, counting to infinity 6.02 Spring 20 Lecture,

More information

Overview 4.2: Routing

Overview 4.2: Routing Overview 4.2: Routing Forwarding vs Routing forwarding: to select an output port based on destination address and routing table routing: process by which routing table is built Network as a Graph A 6 1

More information

Third Generation Routers

Third Generation Routers IP orwarding 5-5- omputer Networking 5- Lecture : Routing Peter Steenkiste all www.cs.cmu.edu/~prs/5-- The Story So ar IP addresses are structured to reflect Internet structure IP packet headers carry

More information

ITEC310 Computer Networks II

ITEC310 Computer Networks II ITEC310 Computer Networks II Chapter 22 Network Layer:, and Routing Department of Information Technology Eastern Mediterranean University Objectives 2/131 After completing this chapter you should be able

More information

CS 421: COMPUTER NETWORKS FALL FINAL January 5, minutes. Name: Student No: TOT

CS 421: COMPUTER NETWORKS FALL FINAL January 5, minutes. Name: Student No: TOT S 421: OMPUTR NTWORKS ALL 2006 INAL January 5, 2007 150 minutes Name: Student No: Q1 Q2 Q3 TOT 1) a) (6 pts) iven the following parameters for a datagram packet switching network: N: number of hops between

More information

Internet Architecture. Network Layer Overview. Fundamental Network Layer Function. Protocol Layering and Data. Computer Networks 9/23/2009

Internet Architecture. Network Layer Overview. Fundamental Network Layer Function. Protocol Layering and Data. Computer Networks 9/23/2009 omputer Networks 9//9 Network Layer Overview Kai Shen Internet rchitecture ottom-up: : electromagnetic signals on the wire : data transfer between neighboring elements encoding, framing, error correction,

More information

CSE/EE 461 Lecture 7 Bridging LANs. Last Two Times. This Time -- Switching (a.k.a. Bridging)

CSE/EE 461 Lecture 7 Bridging LANs. Last Two Times. This Time -- Switching (a.k.a. Bridging) S/ 461 Lecture 7 ridging LNs Last Two Times Medium ccess ontrol (M) protocols Part of the Link Layer t the heart of Local rea Networks (LNs) ow do multiple parties share a wire or the air? Random access

More information

TCOM 501: Networking Theory & Fundamentals. Lecture 11 April 16, 2003 Prof. Yannis A. Korilis

TCOM 501: Networking Theory & Fundamentals. Lecture 11 April 16, 2003 Prof. Yannis A. Korilis TOM 50: Networking Theory & undamentals Lecture pril 6, 2003 Prof. Yannis. Korilis 2 Topics Routing in ata Network Graph Representation of a Network Undirected Graphs Spanning Trees and Minimum Weight

More information

Chapter 22 Network Layer: Delivery, Forwarding, and Routing 22.1

Chapter 22 Network Layer: Delivery, Forwarding, and Routing 22.1 Chapter 22 Network Layer: Delivery, Forwarding, and Routing 22.1 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 22-3 UNICAST ROUTING PROTOCOLS 22.2 A routing

More information

CSE/EE 461 Distance Vector Routing

CSE/EE 461 Distance Vector Routing S/ 46 istance Vector Routing Last Time Introduction to the Network layer Internetworks atagram and virtual circuit services Internet Protocol (IP) packet format The Network layer Provides end-to-end data

More information

COMP 631: NETWORKED & DISTRIBUTED SYSTEMS 9/6/16 COMP 631: NETWORKED & DISTRIBUTED SYSTEMS. Internet Routing. Jasleen Kaur.

COMP 631: NETWORKED & DISTRIBUTED SYSTEMS 9/6/16 COMP 631: NETWORKED & DISTRIBUTED SYSTEMS. Internet Routing. Jasleen Kaur. OMP 3: NETWORKE & ISTRIUTE SSTEMS // OMP 3: NETWORKE & ISTRIUTE SSTEMS Internet Routing Jasleen Kaur Fall 0 Forwarding vs. Routing: Local vs. istributed oth datagram and virtual-circuit based networks

More information

CEN445 Network Protocols and Algorithms. Chapter 2. Routing Algorithms. Dr. Ridha Ouni

CEN445 Network Protocols and Algorithms. Chapter 2. Routing Algorithms. Dr. Ridha Ouni 3/4/04 EN44 Network Protocols and lgorithms hapter Routing lgorithms Dr. Ridha Ouni Department of omputer Engineering ollege of omputer and Information Sciences King Saud University References Some slides

More information

Why dynamic route? (1)

Why dynamic route? (1) Routing Why dynamic route? (1) Static route is ok only when Network is small There is a single connection point to other network No redundant route 2 Why dynamic route? (2) Dynamic Routing Routers update

More information

Minimum Spanning Trees and Shortest Paths

Minimum Spanning Trees and Shortest Paths Minimum Spanning Trees and Shortest Paths Prim's algorithm ijkstra's algorithm November, 017 inda eeren / eoffrey Tien 1 Recall: S spanning tree Starting from vertex 16 9 1 6 10 13 4 3 17 5 11 7 16 13

More information

2/16/2008. Outline Computer Networking Lecture 11 Routing. Sending Link States by Flooding. Link State Protocol Concept

2/16/2008. Outline Computer Networking Lecture 11 Routing. Sending Link States by Flooding. Link State Protocol Concept //8 Outline - omputer Networking Lecture Routing Link tate OP Peter teenkiste epartments of omputer cience and Electrical and omputer Engineering IP Multicast ervice asics - Networking, pring 8 http://www.cs.cmu.edu/~dga/-/8

More information

Introduction to IP Routing. Geoff Huston

Introduction to IP Routing. Geoff Huston Introduction to IP Routing Geoff Huston Routing How do packets get from A to B in the Internet? A Internet B Connectionless Forwarding Each router (switch) makes a LOCAL decision to forward the packet

More information

Fairness Example: high priority for nearby stations Optimality Efficiency overhead

Fairness Example: high priority for nearby stations Optimality Efficiency overhead Routing Requirements: Correctness Simplicity Robustness Under localized failures and overloads Stability React too slow or too fast Fairness Example: high priority for nearby stations Optimality Efficiency

More information

Where we are in the Course

Where we are in the Course Where we are in the ourse More fun in the Network Layer! We ve covered packet forwarding Now we ll learn about roung Applicaon Transport Network Link Physical SE 61 University of Washington 1 Roung versus

More information

COM-208: Computer Networks - Homework 6

COM-208: Computer Networks - Homework 6 COM-208: Computer Networks - Homework 6. (P22) Suppose you are interested in detecting the number of hosts behind a NAT. You observe that the IP layer stamps an identification number sequentially on each

More information

Link-State Routing OSPF

Link-State Routing OSPF CE Computer Networks Link-State Routing OSPF Behnam Momeni Computer Engineering Department Sharif University of Technology Acknowledgments: Lecture slides are from Computer networks course thought by Jennifer

More information

Computer Networks. Routing Algorithms

Computer Networks. Routing Algorithms Computer Networks Routing Algorithms Topics Routing Algorithms Shortest Path (Dijkstra Algorithm) Distance Vector Routing Count to infinity problem Solutions for count to infinity problem Link State Routing

More information

Chapter 12. Routing and Routing Protocols 12-1

Chapter 12. Routing and Routing Protocols 12-1 Chapter 12 Routing and Routing Protocols 12-1 Routing in Circuit Switched Network Many connections will need paths through more than one switch Need to find a route Efficiency Resilience Public telephone

More information

CS4450. Computer Networks: Architecture and Protocols. Lecture 11 Rou+ng: Deep Dive. Spring 2018 Rachit Agarwal

CS4450. Computer Networks: Architecture and Protocols. Lecture 11 Rou+ng: Deep Dive. Spring 2018 Rachit Agarwal CS4450 Computer Networks: Architecture and Protocols Lecture 11 Rou+ng: Deep Dive Spring 2018 Rachit Agarwal 2 Goals for Today s Lecture Learning about Routing Protocols Link State (Global view) Distance

More information

Computer Networks. Routing

Computer Networks. Routing Computer Networks Routing Topics Link State Routing (Continued) Hierarchical Routing Broadcast Routing Sending distinct packets Flooding Multi-destination routing Using spanning tree Reverse path forwarding

More information

CompSci 356: Computer Network Architectures. Lecture 13: Dynamic routing protocols: Link State Chapter 3.3.3, Xiaowei Yang

CompSci 356: Computer Network Architectures. Lecture 13: Dynamic routing protocols: Link State Chapter 3.3.3, Xiaowei Yang CompSci 356: Computer Network Architectures Lecture 13: Dynamic routing protocols: Link State Chapter 3.3.3, 3.2.9 Xiaowei Yang xwy@cs.duke.edu Today Clarification on RIP Link-state routing Algorithm Protocol:

More information

Routing. Routing. Overview. Overview. Routing vs. Forwarding. Why Routing

Routing. Routing. Overview. Overview. Routing vs. Forwarding. Why Routing Routing Dr. Arjan Durresi Department of Computer Science Louisiana State University Overview Routing vs. Forwarding Routing Algorithms, Distance Vector, Link State Dijkstra s Algorithm ARPAnet Routing

More information

Distance Vector: Link Cost Changes. Interdomain Routing. Distance Vector: Count to Infinity Problem. Distance Vector: Poisoned Reverse

Distance Vector: Link Cost Changes. Interdomain Routing. Distance Vector: Count to Infinity Problem. Distance Vector: Poisoned Reverse istance Vector: Link ost hanges 7 loop: Interdomain Routing 8 wait (until sees a link cost change to neighbor V 9 or until receives update from neighbor V) 0 if ((, V) changes by d) for alldestinations

More information

Lecture 13: Link-state Routing. CSE 123: Computer Networks Alex C. Snoeren

Lecture 13: Link-state Routing. CSE 123: Computer Networks Alex C. Snoeren Lecture 3: Link-state Routing CSE 23: Computer Networks Alex C. Snoeren Lecture 3 Overview Routing overview Intra vs. Inter-domain routing Link-state routing protocols 2 Router Tasks Forwarding Move packet

More information

Outline. Routing. Introduction to Wide Area Routing. Classification of Routing Algorithms. Introduction. Broadcasting and Multicasting

Outline. Routing. Introduction to Wide Area Routing. Classification of Routing Algorithms. Introduction. Broadcasting and Multicasting Outline Routing Fundamentals of Computer Networks Guevara Noubir Introduction Broadcasting and Multicasting Shortest Path Unicast Routing Link Weights and Stability F2003, CSG150 Fundamentals of Computer

More information

Destination Sequenced Distance. [Perkins94] CSE 6811 : Lecture 6

Destination Sequenced Distance. [Perkins94] CSE 6811 : Lecture 6 estination Sequenced istance Vector (SV) Routing [Perkins94] SE 6811 : Lecture 6 SV: Proactive SV is a proactive protocol means it maintains up to date routing information for all available nodes in the

More information

CompSci 356: Computer Network Architectures. Lecture 12: Dynamic routing protocols: Link State Chapter Xiaowei Yang

CompSci 356: Computer Network Architectures. Lecture 12: Dynamic routing protocols: Link State Chapter Xiaowei Yang CompSci 356: Computer Network Architectures Lecture 12: Dynamic routing protocols: Link State Chapter 3.3.3 Xiaowei Yang xwy@cs.duke.edu Today Routing Information Protocol Link-state routing Algorithm

More information

From Routing to Traffic Engineering

From Routing to Traffic Engineering 1 From Routing to Traffic Engineering Robert Soulé Advanced Networking Fall 2016 2 In the beginning B Goal: pair-wise connectivity (get packets from A to B) Approach: configure static rules in routers

More information

CSCD 330 Network Programming Spring 2018

CSCD 330 Network Programming Spring 2018 CSCD 330 Network Programming Spring 018 Lecture 16 Network Layer Routing Protocols Reading: Chapter 4 Some slides provided courtesy of J.F Kurose and K.W. Ross, All Rights Reserved, copyright 017 1 Network

More information

Page 1 EEC173B/ECS152C. Link State Routing [Huitema95] Optimized Link State Routing (OLSR) MANET Unicast Routing. Proactive Protocols

Page 1 EEC173B/ECS152C. Link State Routing [Huitema95] Optimized Link State Routing (OLSR) MANET Unicast Routing. Proactive Protocols 173/S152 Proactive Protocols MNT Unicast Routing Proactive Protocols OLSR SV ybrid Protocols Most of the schemes discussed so far are reactive Proactive schemes based on distance vector and link state

More information

CSCD 330 Network Programming Spring 2017

CSCD 330 Network Programming Spring 2017 CSCD 330 Network Programming Spring 017 Lecture 16 Network Layer Routing Protocols Reading: Chapter 4 Some slides provided courtesy of J.F Kurose and K.W. Ross, All Rights Reserved, copyright 1996-007

More information

Chapter 4: Network Layer. TDTS06 Computer networks. Subnets. Subnets. Subnets. IP Addressing: introduction

Chapter 4: Network Layer. TDTS06 Computer networks. Subnets. Subnets. Subnets. IP Addressing: introduction hapter 4: Network Layer TDTS06 omputer s Lecture 6: Network layer III Routing in the Internet Jose M. Peña, jospe@ida.liu.se ID/DIT, LiU 2009-09-16 4. 1 Introduction 4.2 Virtual circuit and datagram s

More information

Section 7: Dijkstra s

Section 7: Dijkstra s Section 7: ijkstra s Slides by lex Mariakakis with material Kellen onohue, avid Mailhot, and an rossman Late days Things to iscuss o cse33-lateday@cs.washington.edu o 3 assignments left o an use late days

More information

Routing. Advanced Computer Networks: Routing 1

Routing. Advanced Computer Networks: Routing 1 Routing Advanced Computer Networks: Routing 1 Gateway To internet or wide area network Metropolitan Area Network (MAN) s s Organization Servers Backbone R S R R Departmental Server s R S R s S R s s s

More information

Routing in Ad-hoc Networks

Routing in Ad-hoc Networks 0/3/ COMP 635: WIRELESS & MOILE COMMUNICTIONS Routing in d-hoc Networks Jasleen Kaur Fall 0 Infrastructure-less Wireless Networks Standard Mobile IP needs an infrastructure Ø Home gent/foreign gent in

More information

Lecture 4. The Network Layer (cont d)

Lecture 4. The Network Layer (cont d) Lecture 4 The Network Layer (cont d) Agenda Routing Tables Unicast and Multicast Routing Protocols Routing Algorithms Link State and Distance Vector Routing Information and Open Shortest Path First Protocols

More information

Routing. Outline. Algorithms Scalability

Routing. Outline. Algorithms Scalability Routing Outline Algorithms Scalability 1 Internetworking What is internetwork An arbitrary collection of networks interconnected to provide some sort of host-host to packet delivery service A simple internetwork

More information

Routing Basics. What is Routing? Routing Components. Path Determination CHAPTER

Routing Basics. What is Routing? Routing Components. Path Determination CHAPTER CHAPTER 5 Routing Basics This chapter introduces the underlying concepts widely used in routing protocols Topics summarized here include routing protocol components and algorithms In addition, the role

More information

Minimum Spanning Trees and Shortest Paths

Minimum Spanning Trees and Shortest Paths Minimum Spanning Trees and Shortest Paths Kruskal's lgorithm Prim's lgorithm Shortest Paths pril 04, 018 inda eeren / eoffrey Tien 1 Kruskal's algorithm ata types for implementation Kruskalslgorithm()

More information

Dynamics of Hot-Potato Routing in IP Networks

Dynamics of Hot-Potato Routing in IP Networks Dynamics of Hot-Potato Routing in IP Networks Jennifer Rexford AT&T Labs Research http://www.research.att.com/~jrex Joint work with Renata Teixeira (UCSD), Aman Shaikh (AT&T), and Timothy Griffin (Intel)

More information

Unit 2. Signaling and Single Area OSPF

Unit 2. Signaling and Single Area OSPF nit ignaling and ingle rea PF elecommunications ignaling ignaling g sed to provide all of the set up, tare down and call processing information such as: ff hook notification alling party number alled party

More information

ECE 544 Protocol Design Project Team Member Names Aneesh Abhyankar Satakshi Tiwari Vishalsingh Hajeri

ECE 544 Protocol Design Project Team Member Names Aneesh Abhyankar Satakshi Tiwari Vishalsingh Hajeri ECE 544 Protocol Design Project 2016 Team Member Names Aneesh Abhyankar Satakshi Tiwari Vishalsingh Hajeri Network Architecture & Topology Assumptions Service Objective: k-out-of-n packet datagram multicast

More information

Unicast Routing. Information About Layer 3 Unicast Routing CHAPTER

Unicast Routing. Information About Layer 3 Unicast Routing CHAPTER CHAPTER 1 This chapter introduces the underlying concepts for Layer 3 unicast routing protocols in Cisco 1000 Series Connected Grid Routers (hereafter referred to as the Cisco CG-OS router) and WAN backhaul

More information

CS4450. Computer Networks: Architecture and Protocols. Lecture 15 BGP. Spring 2018 Rachit Agarwal

CS4450. Computer Networks: Architecture and Protocols. Lecture 15 BGP. Spring 2018 Rachit Agarwal CS4450 Computer Networks: Architecture and Protocols Lecture 15 BGP Spring 2018 Rachit Agarwal Autonomous System (AS) or Domain Region of a network under a single administrative entity Border Routers Interior

More information

Routing in a network

Routing in a network Routing in a network Focus is small to medium size networks, not yet the Internet Overview Then Distance vector algorithm (RIP) Link state algorithm (OSPF) Talk about routing more generally E.g., cost

More information

Initialization: Loop until all nodes in N

Initialization: Loop until all nodes in N Routing Routing lgorithm classification Routing protocol Goal: determine good path (sequence of routers) thru netork from source to dest. Graph abstraction for routing s: graph nodes are routers graph

More information

Network Layer, Part 2 Routing. Terminology

Network Layer, Part 2 Routing. Terminology Network Layer, Part Routing These slides are created by Dr. Huang of George Mason University. Students registered in Dr. Huang s courses at GMU can make a single machine readable copy and print a single

More information

Network Layer: Routing

Network Layer: Routing Network Layer: Routing The Problem A B R 1 R 2 R 4 R 3 Goal: for each destination, compute next hop 1 Lecture 9 2 Basic Assumptions Trivial solution: Flooding Dynamic environment: links and routers unreliable:

More information

Course Routing Classification Properties Routing Protocols 1/39

Course Routing Classification Properties Routing Protocols 1/39 Course 8 3. Routing Classification Properties Routing Protocols 1/39 Routing Algorithms Types Static versus dynamic Single-path versus multipath Flat versus hierarchical Host-intelligent versus router-intelligent

More information

Communication Networks

Communication Networks ommunication Networks Prof. Laurent Vanbever ommunication Networks Spring 08 Roland Meier / Thomas Holterbach Slides: Laurent Vanbever nsg.ee.ethz.ch TH ürich (-ITT) pril 9 08 Materials inspired from Scott

More information

Deployment of IGRP/EIGRP

Deployment of IGRP/EIGRP 1 eployment of IGRP/EIGRP Session 2 Presentation_I.scr 1 Understanding EIGRP Understanding and deploying EIGRP is like driving a car 3 genda Fundamentals of EIGRP UL Summarization and Load alancing EIGRP/IGRP

More information

Redes de Computadores. Shortest Paths in Networks

Redes de Computadores. Shortest Paths in Networks Redes de Computadores Shortest Paths in Networks Manuel P. Ricardo Faculdade de Engenharia da Universidade do Porto » What is a graph?» What is a spanning tree?» What is a shortest path tree?» How are

More information

OSPF Protocol Overview on page 187. OSPF Standards on page 188. OSPF Area Terminology on page 188. OSPF Routing Algorithm on page 190

OSPF Protocol Overview on page 187. OSPF Standards on page 188. OSPF Area Terminology on page 188. OSPF Routing Algorithm on page 190 Chapter 17 OSPF Protocol Overview The Open Shortest Path First (OSPF) protocol is an interior gateway protocol (IGP) that routes packets within a single autonomous system (AS). OSPF uses link-state information

More information

Routing Outline. EECS 122, Lecture 15

Routing Outline. EECS 122, Lecture 15 Fall & Walrand Lecture 5 Outline EECS, Lecture 5 Kevin Fall kfall@cs.berkeley.edu Jean Walrand wlr@eecs.berkeley.edu Definition/Key Questions Distance Vector Link State Comparison Variations EECS - Fall

More information

CHAPTER 4: ROUTING DYNAMIC. Routing & Switching

CHAPTER 4: ROUTING DYNAMIC. Routing & Switching CHAPTER 4: ROUTING DYNAMIC Routing & Switching CHAPTER4 4.1 Dynamic Routing Protocols 4.2 Distance Vector Dynamic Routing 4.3 RIP and RIPng Routing 4.4 Link-State Dynamic Routing 4.5 The Routing Table

More information

Overview. Information About Layer 3 Unicast Routing. Send document comments to CHAPTER

Overview. Information About Layer 3 Unicast Routing. Send document comments to CHAPTER CHAPTER 1 This chapter introduces the basic concepts for Layer 3 unicast routing protocols in Cisco NX-OS. This chapter includes the following sections: Information About Layer 3 Unicast Routing, page

More information

Address Translation. Map IP addresses into physical addresses destination host next hop router

Address Translation. Map IP addresses into physical addresses destination host next hop router Address Translation Map IP addresses into physical addresses destination host next hop router Techniques encode physical address in host part of IP address table-based ARP table of IP to physical address

More information

Inter-networking. Problem. 3&4-Internetworking.key - September 20, LAN s are great but. We want to connect them together. ...

Inter-networking. Problem. 3&4-Internetworking.key - September 20, LAN s are great but. We want to connect them together. ... 1 Inter-networking COS 460 & 540 2 Problem 3 LAN s are great but We want to connect them together...across the world Inter-networking 4 Internet Protocol (IP) Routing The Internet Multicast* Multi-protocol

More information

What is it? Basics. Moving from DigiComms I. Digital Communications II

What is it? Basics. Moving from DigiComms I. Digital Communications II What is it? Routing igital ommunications II Process of finding a path from a source to every destination in the network Suppose you want to connect to ntarctica from your desktop What route should you

More information

CS 5114 Network Programming Languages Control Plane. Nate Foster Cornell University Spring 2013

CS 5114 Network Programming Languages Control Plane. Nate Foster Cornell University Spring 2013 CS 5 Network Programming Languages Control Plane http://www.flickr.com/photos/rofi/0979/ Nate Foster Cornell University Spring 0 Based on lecture notes by Jennifer Rexford and Michael Freedman Announcements

More information